Spark plug



E. STERN SPARK PLUG May 13, 1930.

Filed 'Jan '7, 1928 Patented May 13, 1930 EMERICH STERN, F TEMISOARA,RUMANIA SPARK PLUG Application filed January 7, 1928, Serial No.245,162, and in Austria April 27, 1927.

This invention relates to improvements in spark plugs which essentiallyconsist in that a clan'iping device is conductingly connected with thescrew-threaded end of a spark plug, whereby one'or moreremovableelectrodes are inserted in and fixed in position bythe saidclampingdevice. In case the spark plug is contaminated with oil or soot, theelectrode'can be removed in a most simple manner, cleaned andre-inserted into the spark plug or replaced by another electrode.

Further the present invention relates to a' tool for inserting theremovable electrode in- 1 to the clamping device of the spark plug.

The present invention is illustrated by way of example on theaccompanying sheet of drawings in which:-

Figs. 1 and 2 show a spark plug in partsectional elevation and ininvertedplan view respectively.

Fig 3 shows a tool for inserting the electrode in the spark plug.

Flexible arms 3 of a conducting material and provided with notches ordepressions 2, are secured to the screw-threaded end 1 of the spark plugin any convenient manner. An annular electrode 4, introduced into thenotches 2, is clamped in position by the said 3 flexible arms 3, whichform a clamping device, and the ignition pin 5 of the spark plug passesthrough the central hole of the electrode. In case the spark plug iscontaminated with oil or soot, the resilient arms 3 are forced outwardto such an extent, that the annular electrode 4 drops out. Now thelatter, as well as the spark plug can be cleaned, and the cleanedelectrode or a spare electrode is forced into the resilient clampingdevice. I

A tool illustrated in Fig. 3 facilitates the insertion of the electrodein theclamping device. The former consists of a handle 6, a flange 7formed upon or secured thereto in termediately of its ends, and at itsother end is fashioned as a pin 8, which is provided with a hole orexcavation 9 for the admission of the ignition pin 5 of the spark plug.The annular electrode 4 is placed onto the flange 7 and now the tooltogether with the troduction of the electrode is rendered possible in amost simple manner by the aid of the tool above mentioned.

I claim 1. A spark plug comprising a resiliently expansible clampingdevice conductingly connected with the screw-threaded end of the sparkplug, and an electrode removably inserted in and yieldingly held inposition by the said clamping device.

2. In a spark plug, a plurality of damp ing elements flexibly projectingfrom its screw-threaded end, and an electrode detachably clamped inposition between the said clamping elements.

3. A spark plug comprising flexible conducting arms circumferentiallyarranged and connected with the screw-threaded end of the spark plug,said arms being fashioned with opposite notches and a removable annularelectrode inserted between and secured in position by the said arms.

In testimony whereof I afiix my signature.

EMERICI-I STERN.

